[1] Department of Obstetrics and Gynaecology, Academic Medical Centre, University of Amsterdam, Amsterdam
[2] Department of Obstetrics and Gynaecology, Medical Centre Alkmaar, Alkmaar
[3] Department of Obstetrics and Gynaecology, Maxima Medical Centre, Veldhoven
[4] Department of Obstetrics and Gynaecology, Boven IJ Hospital, Amsterdam
[5] Department of Obstetrics and Gynaecology, Zaans Medical Centre, Zaandam
[6] Department of Obstetrics and Gynaecology, Spaarne Hospital, Hoofddorp
[7] Department of Obstetrics and Gynaecology, Gemini Hospital, Den Helder
[8] Department of Obstetrics and Gynaecology, Deventer Hospital, Deventer
[9] Department of Obstetrics and Gynaecology, Kennemer Gasthuis, Haarlem
[10] Department of Obstetrics and Gynaecology, Erasmus Medical Centre, Rotterdam
[11] Department of Obstetrics and Gynaecology, Onze Lieve Vrouwe Gasthuis, Amsterdam
[12] Department of Obstetrics and Gynaecology, Tergooi Hospital, Blaricum
[13] Centre for Reproductive Medicine, Academic Medical Centre, University of Amsterdam, Amsterdam